Table 4.

Liver Iron Quantification

Description	T2w Coronal	T1w In/ Out	T2w FatSat	DWI b= 0, 50, 500	T1w Axial	T2*MAP In-Phase	T2*MAP Short ET	T2*MAP Long ET
Sequence	SSFSE	2D SPGR	FRFSE	EPI	3D SPGR	2D GRE	2D GRE	2D GRE
Plane	Coronal	Axial	Axial	Axial	Axial	Axial	Axial	Axial
Slice thickness (mm)	5	7	7	7	5	10 (3 slices)	10 (3 slices)	10 (3 slices)
Gap (mm)	0	1	1	1	−2.5	2	2	2
Fat suppression	–	–	Spectr.	(Spectr.)	IR	–	–	–
TE1/TE2 (ms) (out/in)	100	2.2/4.4	102	Min (<90)	?	1.9; 4.7; 7.5; 10.2; 13; 15.8; 18.5; 21.3	0.9; 1.8; 2.8; 3.8; 4.8; 5.8	0.9; 2.0; 3.1; 4.2; 5.3; 6.4; 7.6; 8.7; 9.8; 10.9; 12; 13.1
TR (ms)	–	210	2500	4000 (2000)	?	−40	35.5	35.5
Flip angle	90	90	90	90	12	25	12	12
ETL	–	–	15	–	–	–	–	–
NEX	0.5	1	1	1 (12)	<1	1	1	1
Phase enc. steps	320	256	256	128	256	384	128	104
Frequency steps	192	128	160	128	192	192	64	104
Breath	BH	BH	BH	BH/Trig.	BH	BH	BH	BH
Notes						8 echoes	6 echoes	12 echoes

After basic sequences for evaluation of liver parenchyma, 3 multiecho T2*-weighted sequences are acquired to obtain good accuracy in estimation. In the first T2*-weighted series, ETs are set approximately within water and fat phase coherence, whereas in short ET the first echo time is <1 ms to investigate higher iron concentrations. The long ET series is designed to investigate lower iron concentrations. BH, breath-hold; Dixon, Dixon technique; enc., encoding; ETL, echo train length; FSE, fast spin echo; In/out, in-phase and out-of-phase; IR, inversion recovery; NEX, number of excitations; Spectr., chemically selective fat suppression; SSFSE, half Fourier single-shot FSE. Trig., respiratory triggering; w, weighted.